The sudden military build-up in support of Mr Al Assad and a refugee crisis that has spilled into Europe have lent new urgency to resolving the Syria war.
The United States has a $500-million programme to train and equip vetted moderates recruited from among the rebels fighting Assad, but it has faced repeated setbacks.
Putin made the comments ahead of his scheduled Monday address to the UN.
The president of Iran – which also backs Assad – is among other leaders at the UN.
In a US TV interview, Mr Putin said he had no plans “right now” to deploy combat troops in Syria, amid U.S. concerns about a Russian military build-up.
“He can’t be a part of Syria’s long-term future”.
“We have been providing assistance to legitimate government entities only,” he said.
“He can’t play a part in the future of Syria and that position hasn’t changed”.
Asked if he believed Assad should face prosecution at the ICC, Mr Cameron said: “People who break global law should be subject to worldwide law”.
Meanwhile, French President Francois Hollande said with his nation’s first airstrikes it “struck in Syria this morning an Islamic State training camp which threatened the security of our country“.
Abadi’s spokesman said enhanced intelligence cooperation would positively affect operations against Islamic State, which proclaimed a “caliphate” straddling Syria and Iraq previous year.
“Moscow’s recent moves in Syria are an attempt to place it at the center of the world stage”, said one USA official who spoke only on the condition of anonymity. Prior to that, Obama and Putin briefly discussed the crisis in Ukraine in June during the 70th anniversary of D-Day.
Obama used his remarks to call on Republicans to work with Democrats on a new spending plan, and said the GOP should be open to expanding spending, especially since budget deficits have fallen while he’s been in office. He touted his administration’s efforts to restore ties with Cuba after a half-century freeze and the completion of a nuclear accord with Iran, noting that Russian Federation was a key partner in negotiating the Iran deal. He added that Obama decided “that it was worth it at this point to engage with President Putin in a face-to-face meeting to see if the interests of the United States could be advanced”.
“After the end of the Cold War, the single center of domination has emerged in the world”, Putin said. Seated at the same table, they clinked glasses during a toast, with Putin smiling and Obama grim-faced.
Addressing another area of tension with Russian Federation, the USA president defended Western sanctions against Moscow for its actions supporting rebels in Ukraine.
Despite little sign of a breakthrough on either front, USA officials insisted it was still worthwhile for the leaders to meet – something that has happened rarely since Obama vowed to isolate Putin in retaliation for Russia’s provocations in Ukraine.